get the rear wheels off the ground , see is either wheel has excess play, if you can tell which side is making the naise go around a curve (UNLOADING) the side that nakes noise may help pinpointing which side is noisy , its going to be a wheel bearing rear , or change both sides

Hi nulu,

There is no change in noise from driving straight or cornering the car..... otherwise the diagnosis would be easier.
The whining sound is the same no matter the load on the wheels.
I checked the rear end on the lift and there is no noticeable play at all but I remember that it is very hard to detect the condition of the bearings unless they are very much run down.
Martin

then try a stethescope on my 94 124 wagon one side was slightly loose , i replace that bearing , but noise still there, ended up changing both noise now gone

Noises can be so confusing. I guess I am planning on replacing both sides.
I cannot sense any extended play but something is obviously off and I need to act.
What special tools are needed for the job?

Best, Martin